Abstract: At approximately 9:30 a.m. on June 13, 2006, Employee #1, an equipment operator, was operating a backhoe to excavate a wall. After excavating an area measuring 7 feet deep by 22 feet long by 21 feet wide, Employee #1 exited the backhoe and entered the excavation area to do some hand grading in order to better expose a previously buried conduit. The soil of the excavation was made up of silt and sand with embedded rock. The embedded rock had been previously excavated. In addition, the soil was wet due to rainy conditions. As Employee #1 was hand digging in the excavated trench, a large rock became dislodged and struck him. Loose material then caved in around Employee #1 and the rock. Employee #1 was taken to Tahoe Truckee Hospital, where he was hospitalized and treated for fractures to both of his hip sockets. The accident investigation determined that a compilation of the soil conditions, rainy weather, and vibrations caused by the large excavator working nearby, were the root cause of the cave in. Employee #1 had been instructed by his employer not to enter the excavated area.